Embodiments of the present invention relate to long-lasting liquid color formulations for application to the skin and methods for manufacturing such formulations.
Colorant materials have been used for many years to highlight the lips and other skin regions on the body. Most conventional lipstick formulations have a semisolid consistency, and include a colorant such as a pigment mixed with an oily vehicle such as a fat or oil stiffened to a desired consistency with one or more waxes. In recent years, attempts have been made to provide a lipstick having a long lasting color, in order to lessen the need for frequent reapplication and to avoid problems such as the lipstick rubbing off of the lips and onto clothing.
One type of lipstick formulation increases the concentration of the colorant in an effort to obtain long lasting color. However, increasing the concentration of the colorant can cause the lipstick to become too dry on the lips. Moisturizers and conditioning agents can be added to the formulations, but these components are not durable and can adversely affect the appearance of the lipstick on the lips.
Another type of lipstick formulation includes a ceramide component. Ceramides are a group of lipids, members of which are found in the epidermis of mammals. Chemically, ceramides are N-acrylated sphingosine bases. Ceramide lipstick formulations also typically contain hydrocarbon waxes. Such formulations may provide some improvement, but even longer wear lipstick formulations are desirable.
Colorants used for application to skin other than the lips, such as tattoos on the arms, may be injected into the skin in order to form a permanent tattoo. Other colorant formulations (like magic marker ink) may be used to stain the skin for a relatively short time period, for example, a few hours. It would be desirable to be able to color the skin for a longer time period, while at the same time not permanently staining the skin.
Embodiments of the present invention provide a liquid lipstick including effective amounts of a copolymer having an acrylate/methacrylate component, an N-substituted acrylamide component, and an unsaturated carboxylic acid component. The liquid lipstick also includes a cellulose material, and at least one alcohol. The cellulose material may be hydroxypropylcellulose. One or more colorant materials may be included in the composition, and other additives may be added to enhance properties such as the feel of the composition on the lips. Additional additives such as fragrance and botanical extracts may also be added. Such compositions can be easily applied to the lips and offer long wear characteristics.
Other embodiments include a liquid colorant composition for coloring skin. The composition includes an acrylates/octylacrylamide copolymer consisting essentially of 10-75% by weight acrylate/methacrylate, 10-70% by weight N-substituted acrylamide and 5-40% by weight unsaturated carboxylic acid. The composition also includes a thickener material, alcohol and colorant.
Another embodiment relates to a liquid composition for coloring skin including effective amounts of an acrylates/octylacrylamide copolymer having an acrylate/methacrylate component, an N-substituted acrylamide component and an unsaturated carboxylic acid component. The embodiment also includes hydroxypropylcelluose as a thickener. Additional ingredients include isostearyl alcohol, ethanol, and colorant.